#26 Add quick lime (CaO) to water carefully and slowly -- dedicated to Armando. Mixing CaO with water as a means of producing kalkwasser generates an enormous amount of heat from the chemical reaction.
#25- Always give yourself more time than you think it would take when cleanning, fixing things, re-aquascape, water change, etc. For some reason, it always take more time than you expected. And dont leave the job half finished!
#20 Never buy something that will depend on something you don't already have (i.e. "That tang will be fine until I can get my big tank"; "The coral will be fine, I'm getting better lights soon anyway", "I'm sure that jawfish will be OK until I add more sand"; and too many others!)
#19 Teflon tape saves lives (and hardwood floors)
#18 Get other members experiences with an animal/product before you bring it home, not after.
#12 And make sure that stand is level. Aquariums will easily twist to fit an uneven surface. This greatly comprimises their integrity and increases the chance of them unzipping in your living room; flooding and warping your precious hard wood floors with sea water, and costing you thousands of dollars in damage.